Magnetic ferrite, such as spinel type ferrite that has iron oxide, zinc oxide, nickel oxide and magnesium oxide as the main ingredients, has been used as magnetic core material for magnetic elements for use in electronic circuits. These magnetic core materials are used in magnetic elements to be used in low frequency electronic circuits up to circuits operating at 200 MHz by adjusting the compounding ratio of the main ingredients based on Mn—Zn ferrite, Ni—Zn ferrite or Mg ferrite and the amount of additives. The magnetic elements used in these electronic circuits realize various characteristics by utilizing complex magnetic permeability μ=μ′−μ″×I (μ′: magnetic permeability; μ″: loss component) of the magnetic ferrite used as the magnetic core.
Furthermore, as illustrated in Japanese Patent Laid-Open Application JP H05-36517, magnetic elements that use hexagonal ferrite having iron oxide, barium oxide and strontium oxide as the main ingredients are recently used in electronic circuits operating in frequency bands beyond 200 MHz.
However, with the conventional magnetic ferrite, as the loss component μ″ drastically increases at frequencies below 1 GHz, the limit of use of magnetic elements that use conventional magnetic ferrite as the magnetic core is 1 GHz. On the other hand, advances in the technology toward higher frequencies in association with a trend of digitization of electronic equipment that use these magnetic elements are remarkable. As a result, it is important to realize components that can cope with higher frequencies in order to process high-speed and large-capacity signals.